Factor structure of the developmental behavior checklist using confirmatory factor analysis of polytomous items.

The Developmental Behavior Checklist (DBC; Einfeld and Tonge, 1995) is a 95 item clinical screening checklist designed to assess the extent of behavioral and emotional disturbance in populations with intellectual deficit (ID). The DBC provides five principal-component derived subscales covering clinically relevant dimensions of psychopathology (i.e., Disruptive, Self-Absorbed, Communication Disturbance, Anxiety, and Social Relating). Validating these subscales for individual differences research requires examinations of the stability of this structure. This study begins a program of psychometric study of the DBC, by utilizing item level data to investigate the DBC's subscale structure in regard to simple-structure restrictions, as well as the implications of factorially complex items for inter-subscale correlations. To accomplish these goals a polytomous confirmatory factor analysis (PCFA) of the DBC was performed, and the pattern of loadings and inter-factor correlations was examined with and without simple-structure restrictions. Our findings provide evidence that the two largest subscales (Disruptive/Antisocial, Self Absorbed) are well behaved in PCFA models and should exhibit little bias under unit-weighted scoring procedures, or in latent factor models. Findings for the three smaller subscales (Communication Disturbance, Social Relating, and Anxiety) do not invalidate their use in individual differences research, but do highlight several issues that should be considered by individual differences researchers.